Several genetic and immunologic mechanisms involved in the control of antibody and complement production are under study. The mechanism of immunoglobulin allotype suppression is being investigated with particular reference to identifying all of the humoral constituents of the reaction. The genetic control of complement components in the mouse is also under study. The influence of H-2 complex genes on the early components of the classical complement system is being elucidated. BIBLIOGRAPHIC REFERENCE: Keller, R., Peitchel, R., Goldman, J.N. and Goldman, M.B.: An IgG-Fc receptor induced in cytomegalovirus infected human fibroblasts. J. Immunol. 116:772, 1976.